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avutil/md5: fix misaligned reads

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This makes ubsan happy and also considerably increases performance on
big endian systems.

Tested on an IBM POWER7 3.55 GHz

Before:

2.24user 0.14system 0:02.39elapsed 99%CPU (0avgtext+0avgdata 2624maxresident)k
2.26user 0.11system 0:02.38elapsed 99%CPU (0avgtext+0avgdata 2688maxresident)k
2.23user 0.15system 0:02.38elapsed 99%CPU (0avgtext+0avgdata 2624maxresident)k
2.25user 0.12system 0:02.38elapsed 100%CPU (0avgtext+0avgdata 2624maxresident)k
2.20user 0.15system 0:02.36elapsed 99%CPU (0avgtext+0avgdata 2624maxresident)k

After:

1.86user 0.13system 0:02.00elapsed 99%CPU (0avgtext+0avgdata 2624maxresident)k
1.89user 0.11system 0:02.01elapsed 99%CPU (0avgtext+0avgdata 2624maxresident)k
1.85user 0.14system 0:02.00elapsed 99%CPU (0avgtext+0avgdata 2624maxresident)k
1.84user 0.15system 0:01.99elapsed 99%CPU (0avgtext+0avgdata 2624maxresident)k
1.89user 0.13system 0:02.02elapsed 99%CPU (0avgtext+0avgdata 2688maxresident)k

Tested-by: Nicolas George <george@nsup.org>
Reviewed-by: Michael Niedermayer <michael@niedermayer.cc>
Signed-off-by: James Almer <jamrial@gmail.com>
Signed-off-by: Sean McGovern <gseanmcg@gmail.com>
This commit is contained in:
James Almer 2017-03-03 00:25:54 -03:00 committed by Sean McGovern
parent 61cec5adaa
commit a876958d0f
1 changed files with 8 additions and 12 deletions
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20
libavutil/md5.c
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@ -83,15 +83,15 @@ static const uint32_t T[64] = { // T[i]= fabs(sin(i+1)<<32)
a += T[i]; \
\
if (i < 32) { \
if (i < 16) \
a += (d ^ (b & (c ^ d))) + X[i & 15]; \
else \
a += (c ^ (d & (c ^ b))) + X[(1 + 5 * i) & 15]; \
if (i < 16) \
a += (d ^ (b & (c ^ d))) + AV_RL32(X + (i & 15)); \
else \
a += (c ^ (d & (c ^ b))) + AV_RL32(X + ((1 + 5 * i) & 15)); \
} else { \
if (i < 48) \
a += (b ^ c ^ d) + X[(5 + 3 * i) & 15]; \
a += (b ^ c ^ d) + AV_RL32(X + ((5 + 3 * i) & 15)); \
else \
a += (c ^ (b | ~d)) + X[(7 * i) & 15]; \
a += (c ^ (b | ~d)) + AV_RL32(X + ((7 * i) & 15)); \
} \
a = b + (a << t | a >> (32 - t)); \
} while (0)
@ -99,18 +99,14 @@ static const uint32_t T[64] = { // T[i]= fabs(sin(i+1)<<32)
static void body(uint32_t ABCD[4], uint32_t X[16])
{
int t;
int i av_unused;
unsigned int a = ABCD[3];
unsigned int b = ABCD[2];
unsigned int c = ABCD[1];
unsigned int d = ABCD[0];
#if HAVE_BIGENDIAN
for (i = 0; i < 16; i++)
X[i] = av_bswap32(X[i]);
#endif
#if CONFIG_SMALL
int i;
for (i = 0; i < 64; i++) {
CORE(i, a, b, c, d);
t = d;